The need to reduce fuel consumption and emissions in automobiles and other vehicles is well known. Therefore, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle currently being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles in that they are selectively driven by one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to drive the vehicle.
It is known to use an electric machine to decelerate an electrified vehicle. This is commonly referred to as regenerative braking. Regenerative braking can be achieved during braking or lift pedal conditions by configuring the electric machine as a generator. The act of generating power with the electric machine creates a negative braking torque, or regenerative torque, on the electric machine. The negative torque is transmitted to the drive wheels to slow the electrified vehicle.
Drivers of electrified vehicles can apply a brake pedal so abruptly or assertively that a system regeneration limit is exceeded, thereby forcing friction brakes of the vehicle to apply the decelerative wheel torque. If braking is too aggressive, regeneration energy is lost to the vehicle friction brakes, which may reduce fuel economy.